This application relates to compositions and methods for the treatment of prostate and other cancers that express elevated levels of hsp 27 as compared to normal tissue in at least some stages of disease development.
Prostate cancer is the most common cancer that affects men, and the second leading cause of cancer deaths in men in the Western world. Because prostate cancer is an androgen-sensitive tumor, androgen withdrawal, for example via castration, is utilized in some therapeutic regimens for patients with advanced prostate cancer. Androgen withdrawal leads to extensive apoptosis in the prostate tumor, and hence to a regression of the disease. However, castration-induced apoptosis is not complete, and a progression of surviving tumor cells to androgen-independence ultimately occurs. This progression is the main obstacle to improving survival and quality of life, and efforts have therefore been made to target androgen-independent cells. These efforts have focused on non-hormonal therapies targeted against androgen-independent tumor cells (Yagoda et al., Cancer 71 (Supp. 3): 1098-1109 (1993); Oh et al. J. Urol. 60: 1220-1229 (1998)), however, so far no non-hormonal agent has improved survival. Alternative approaches are therefore indicated.
It has been observed that numerous proteins are expressed in increased amounts by prostate tumor cells following androgen withdrawal. At least some of these proteins are assumed to be associated with the observed apoptotic cell death which is observed upon androgen withdrawal. (Raffo et al., Cancer Res.: 4448-4445 (1995): Krajewska et al., Am. J. Pathol. 148: 1567-1576 (1996); McDonnell et al., Cancer Res. 52: 6940-6944 (1992)).